


Miscalculation

by Astriferous (NiisanSavior)



Category: Undertale (Video Game)
Genre: Alternate Universe - Underfell, Alternate Universe - Underswap, Alternative Universe - Horrortale, Alternative Universe - Swapfell, Alternative Universe - Underlust, Assuming Consent, BASICALLY SANS HAS A BAD TIME, Creampie, Crying, Cunnilingus, Degradation, Delusions, Dom/sub, Double Penetration, Ecto-Genitalia (Undertale), Ecto-Penis (Undertale), Ecto-Tongue (Undertale), Ecto-Vagina (Undertale), Extremely Dubious Consent, Face-Sitting, Forced Bonding, Gang Rape, Genital Piercing, Guilt, Humiliation, Kinks, Knotting, M/M, Master/Pet, Mating Cycles/In Heat, Mind Break, Multi, Murder, Orgasm Delay/Denial, Orgy, Other Additional Tags to Be Added, Overstimulation, Oviposition, Pet Names, Piercings, Possessive Behavior, Praise Kink, Public Sex, Rough Sex, Sex Toys, Sexual Conditioning, Size Difference, Somnophilia, Soul Bond, Suicide Attempt, THIS IS REALLY AN EXCUSE FOR ME TO WRITE CLASSIC SANS GETTIGN FUCKED, Teleportation, Tentacle Monsters, Tentacle Rape, Tentacle Sex, Tentacles, Unhealthy Relationships, Wall Sex, bara red kinda..?, for us chapter, i try to reply to everyone and i love chatting, if you leave a comment expect a reply, pls god read the note in the first chapter otherwise you're gonna be so confused, the first chapter is intentionally short, the rest is basically hard noncon
Language: English
Status: In-Progress
Published: 2018-02-20
Updated: 2018-05-15
Packaged: 2019-03-21 16:17:16
Rating: Explicit
Warnings: Rape/Non-Con
Chapters: 11
Words: 15,951
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/13744671
Author URL: https://archiveofourown.org/users/NiisanSavior/pseuds/Astriferous
Summary: Sans visits a different timeline out of pure curiosity.The fact his heat was literally just around the corner just slipped his mind.





	1. Chapter 1

**Author's Note:**

> OKAY! So whatever chapter you pick after this us what universe you wanted to see Sans travel too! These chapters are not in chronological order!! They depend on what the reader wants to see!!  
> If you want to see Sans in a certain universe while in heat, leave a comment suggesting it!  
> Also I'm planning sequels to each short story so you all know what happens to Sans in each timeline!  
> Here is your final warning for fucked up shit its not super super happy!

Sans stared at the machine before him, which had just whirred to life before him. He grinned tiredly, scanning his notes to double check his math. If he was correct, this machine should send him into alternative timelines.  
Alphys had helped him partially with the machine. Sans always had a fascination with manipulating the universe around him, an obsession that he was known for long before Frisk traversed through the underground.  
Sans didn't exactly have a reason why he wanted to travel to other timelines, just wanted to sate his curiosity. Just to see.  
He watches the portal open up slowly, ignoring how he suddenly felt a bit hotter. He pulls at the edge of his sweater underneath his favorite blue jacket, sighing.  
He's waited to long for something like this because he was getting a small fever.  
Finally, the portal fully opens fully, and Sans steps towards it hesitantly. He's already told Alphys where he's going today, but he wonders if he should leave something for papyrus. Just in case.  
Sans shakes his head to clear his thoughts. He should be back in a few hours, Papyrus will be fine.  
He takes another step towards the machine, takes a deep breath, then fully walks through.


	2. Red Hot (Underfell)

**Summary for the Chapter:**

> "maybe it's just narcissism, but you're so pretty, sweetheart. and smelling like this, how can i resist?"

**Notes for the Chapter:**

> check end for more detailed warnings!

Sans lets out a small squeak of surprise as he blinks back into existence, falling momentarily into the air before landing on something decidedly not soft. He groans, opening his eyes slowly. He sees snow first, fuck, wasn't he supposed to teleport into this universe's version of the lab? His eye lights begin to take the somewhat familiar surroundings, before looking at what exactly he's fallen onto-

"heya, sweetheart."

or, whoever he fell onto.

Sans startles, his back hitting the edge of this universe's version of his sentry post as he flung himself back in alarm, staring up at a much rougher version of himself. This one appears to be quite taller than Sans, with a black fluffy jacket and a red sweater underneath. His eye lights wandered further up to the others face. taking him in as this alternative version smirked down at him. Sans's eyes moved from his golden tooth, to his red eye lights, to the crack winding up from the right eye socket.

"hey, it's rude to stare."

Sans blinked again, shaking his head. "what..?" He glanced around once more, before turning back at the larger version of himself.

"what happened..?"

The other laughed, grinning. "ya appear out of thin air, land on my lap.." He reaches out to touch the side of Sans's cheekbone. "ya look just like me, and ya expect me to understand?"

Sans winced at the feeling of being "Checked" washed over him. He always hated feeling like he was on display.

Sans sighed. "ok, ok stupid question.." He moved his arms to try to pull himself out of the others lap and onto the top of the sentry station, but he was held in place his alternate, who had one hand on Sans's shoulder, the other on his pelvis.

Sans blushed lightly, the contact feeling.. nice..?

"th' name's sans." His other self introduced. "sans the skeleton." Sans stared at his red self, dumbstruck.

"fuck, my name is sans.." He said breathlessly.

 

the other smirked. "that's going to get confusing real fast."

"alright, then how about a nickname?"

"fine, but i have to give ya a nickname." Sans nodded. That's fair, it's his universe after all.

"lil' blue."

"creative." Sans glared at the other's smirking face.

"suits ya." Was all he answered with.

Sans, mentally referring to the other as "Red" as to not confuse himself. He was about to open his mouth to further question the other, before stopping himself with a sharp cry. His soul suddenly spiked in heat. He clung against the other, heat overriding his body.

"holy fuck.." he heard Red above him, but Sans was too focused on how his magic snapped into existence without warning. His quivering lips were dripping, begging for someone to help him through his heat.

Sans panted, crying out again. "f-fuck, fuck, i thought i still h-had a week, shit-!" Sans's ramblings where cut off by Red picking him up and slamming him onto the table of his sentry post.

"fuck, lil' blue, you really were made for me.." Red mumbled, hovering over the other, gently but firmly pinning Sans wrists to the wood with one hand. Sans let out a cry of alarm and confusion, feeling Red beginning to strip him of his jacket. "you come out of nowhere, in heat, stats so unbelievably low, basically begging for someone to take and protect you.." Red parts his teeth, licking his red ecto-tongue against Sans's closed teeth. Sans whined, unwittingly parting his own teeth. His own ecto-tongue formed soon after, letting Red lead him into a deep kiss.

"maybe it's just narcissism, but you're so pretty, sweetheart. and smelling like this, how can i resist?" Red says as he pulls away, chucking. He tugs away Sans's sweater next, Sans making another noise of fear as his soul was displayed behind his rib cage.

"shh. i won't hurt ya." Red kissed his collarbone, before pulling back to stare at bones. Minus the large scratch running diagonally across his chest, it was unmarked. Red cursed. "shit. yer so fucking beautiful"

 

Sans whined. "p-please, please don't, oh fuck." Tears threatened to spill from the edge of his eye sockets.

Red hushed him again, removing Sans shorts. He grinned, spying Sans's ecto-pussy, which was throbbing and drenched in fluid.  
"yer that wet already?" he flicked the others clit, making Sans gasp and cry out.

Red laughed again, leaning forward to press a kiss against Sans's forehead as he thrust two fingers into his cunt, wasting no time to stretch the other. "yer fuckin' mine, sweetheart." he growled adding in a third finger for good measure, smirking as Sans keened. "my perfect mate.."

Sans shook his head slightly, tears beginning to fall past his cheekbones.

"p-please.." He tried, one last time

Red chuckled. "of course, lil' blue." He pulled his shorts down to reveal his cock, summoned shortly after Sans's heat fully set in. It was much, much thicker than it was long,.

Sans sobbed out when he saw it. "i-it won't fit, you're going t-to break me.." He cried, panicked, acutely aware of his one hp, even in a heat induced state.

Red hushed him, licking over his neck before biting softly. "i won't break ya, sweetheart. trust me." He purred, lining up his cock to the others entrance.

Sans screamed loudly as the other breached him, suddenly beyond thankful for the stretching beforehand as it did slightly help the other push past slowly.

He shuddered at Red bottomed out against him, grunting. "there, you took it beautifully. you were made for me." He kissed the other's forehead.

Sans only came out of a dazed, pained state as he felt his soul being summoned from his body. He jerked up, screaming. "don't!! don't don't fuck please!!" His eye lights were pinpricks as Red summoned his soul above his rib cage, the soul humming happily to get attention while in heat. Sans watched fearfully, openly sobbing as Red summoned his own soul.

Red pushed the two souls together as he began to thrust quicker, Sans's vision whiting out as the sensation of his pussy being pounded into and his soul combining with another mixed and clashed, bringing Sans's to completion. He screamed, the pleasure from cumming quickly being overridden with painful over sensitivity as Red continued to thrust into the other mercilessly, panting as he growled praises and possessive things to Sans, before finishing deep inside the other.

"fuck yes, sweetheart." Red sighed happily, as Sans sobbed at the feeling of being filled with the others magic.

Sans whimpered quietly, finally seeing his soul, now forever stained with the red of his other selves magic. The soul bond was completed.

"yer mine forever, lil' blue."

 

Sans shuddered feeling Red's magic leak out of him as the other pulled out. He blushed vibrantly at the other's staring. "beautiful.." Red breathed, before being interrupted by distant yelling.

"SANS!!" A familiar, distant voice grew nearer. Sans gasped in alarm, jumping up to try to hide despite his aching bones protesting. Red caught him last second, simply turning him around on the sentry post, pushing him onto his knees, spreading his femurs to show his still formed pussy, dripping red magic, and pinned his arms behind his back.

Sans cried out, mortified tears rolling down his face as the other appeared before them.

"THE DOGS ARE COMPLAINING OF A STRONG SMELL FROM YOUR SENTRY POST." This world's version of Papyrus glowered despite the red dusting his cheekbones, glaring at Red's smirking face to Sans. "WHO THE FUCK IS THIS?!"

Red licked against Sans's neck, letting him cry out weakly. "lil' blue." Red answered calmly, rubbing Sans's clit to elicit more moans from the other, watching smugly as his brother was staring at his new mate.

"wanna join us for round two?"

**Notes for the Chapter:**

> noncon! forced soul bonding, possessive behavior, public sex, size difference, panic attacks, praise! Lemme know if i forgot to tag something but i think i got the most serious ones lol


	3. Sleepover (Underswap)

**Summary for the Chapter:**

> "H-He Smells So Good, Papy.." Blueberry whined, grinding roughly against the other. Sans tried to explain to Papryus, but all that came out was a choked moan. "I Want Him To Be Ours.." Sans's soul stuttered in fear.

**Notes for the Chapter:**

> Detailed warnings in end notes!  
> I got a very cute suggestion of the swaps trying to "woo" sans tho so i think i may make another version of this, one where blue like. respects personal space lol

Sans jolted, shivering as he realized he landed in a snow pile. He looked up, recognizing the doors to the ruins immediately. He didn't understand, this looked the same-

"IS THAT A..?!"

Sans jerked at the loud voice, turning to see a version of himself. Sans's eye lights grew wide.

This version of him had lighter blue magic, stars in his huge eyes, and a light blue bandana tied around his neck. This version of him came bouncing over, kneeling before Sans. Sans flinched as his alternate poked his cheek without warning. "WELL, YOU'RE DEFINITELY NOT A HUMAN. BUT ANOTHER COOL SKELETON! A COOL SKELETON WITH A RESEMBLANCE TO MYSELF.." His clone was still grinning, despite his head being tilted in confusion. Sans blinked, overwhelmed by this version of himself. 

In fact, he acted a bit like...

"p..papyrus..?"

The other him gasped.

"YOU KNOW MY BROTHER??"

Sans shook his head, dumbstruck "i, uhm, i'm another version of you, from another universe..?" he tried, before yelling as he was picked up bridal style by the other.

The energetic version of himself grinned, seemingly not heard his attempt at an explanation. "LET'S GO FIND PAPYRUS!"

 

Sans's eye sockets were wide, hands gripping onto the shirt of his double, who he had decided to nickname "Blueberry" as to not confuse himself. How could Blue have so much energy? Blueberry let out a loud "MWEH HEH HEH!" At Sans's dazed expression, allowing the other to steady himself by holding onto his shoulders as Sans was placed on his feet  
again. Blue opened the door to the house that Sans recognized as a copy of his own.

"PAPY!!" Blueberry shouted, pulling Sans into his house. A orange hoodie clad skeleton jerked on the couch, slowly sitting up to stare at Blueberry and Sans, his eye lights widening.

"...what...?"

"I FOUND ANOTHER MAGNIFICENT SANS!!" Berry exclaimed, pulling Sans's face near his own. "CANT YOU SEE THE RESEMBLANCE??" Papyrus's face was hard, staring at the two.

Sans winced at the feeling of being "Checked." The Papyrus's face softened after checking his stats, but his brow bones quirked in confusion.

"sans, it's getting late. you should probably get out of your battle body." Papyrus said, making Blueberry let go of Sans to check the window. Sans turned to see Snowdin darkening. Wasn't it only morning when he teleported..?

Blueberry ran up the stairs, but paused halfway through, turning to Sans. "ARE YOU STAYING THE NIGHT??" He asked excitedly, grin widening.

Papyrus chuckled. "We're going to get that sorted out right now, lil bro." Satisfied, Berry disappeared into his room, leaving Sans and the alternative Papyrus.

Sans turned to see Papyrus's gaze. "explain." Papyrus said coolly. Sans sighed.

"where should i begin?"

 

Sans sat down on the couch by the Papyrus's request, telling him about his machine, how he got it working and how it teleported him here, along with the differences with his universe and theirs.

At the end, Papyrus at least seemed satisfied with the lengthy explanation, slumping back against the couch and pulling a bottle of honey from his pocket. He took a sip, before saying, "my own machine, i haven't had much time for, but with you helping me we can get you home in no time."

Sans sighed in relief. "thank you so much, oh my stars." Papyrus hummed, giving Sans a smile.

"don't mention it." He took another swig of honey.

Sans finally decided on a nickname for the other; Honey.

 

Blueberry came rushing down the stairs shortly afterwards, leaning over the couch to pull Sans and Papyrus into a hug.

"COMIC! ARE YOU STAYING??" Berry questioned enthusiastically.

"comic..?" Sans mumbled, head tilting in confusion before Honey cut him off.

"he's going to be staying for a little while, lil bro. hope you don't mind roommates."

Blueberry grinned only widened.

"why'd you call me comic?" Sans asked again.

"WELL, TWO SANSES IS QUITE CONFUSING! SO I TOOK IT UPON MYSELF TO FIND YOU AN EQUALLY MAGNIFICENT NICKNAME WHILE YOU'RE STAYING HERE!" Berry looked so pleased with himself for finding a nickname, Sans didn't have the heart to refuse him.

"'s a cool name, lil bro." Honey murmured, before standing up. "i'm heading to bed."

Sans yawned, nodding. "i'll hit the hay too. hope you two don't mind me sleeping on the couch-"

"WHAT!! NO!!" Sans startled, looking at Blueberry's pouting face. "YOU SHOULD SLEEP UPSTAIRS IN MY ROOM! IT'LL BE A SLUMBER PARTY!!!"

Again, Sans didn't have the heart to say no.

 

Blueberry ended up being quite a cuddle-er, Sans found, the two laying on Berry's really cool race car bed. He yawned, willing his eyes to close as he tried to get comfortable with Blueberry clinging to his back-

Sans ended up gasping as his soul heated up. He gripped onto his pillow as heat overtook his body, eyes squeezing shut as his mind became fuzzy. Sans whined in displeasure, swearing at himself. He could have sworn he wasn't due for his heat until next week-

He jolted as he felt something rub against him harshly, that being the final straw for his magic to snap into existence. Sans let out a small cry, confused as to what was grinding  
against his pelvis. He craned his neck, blushing harshly as he saw Blueberry beginning to grind against him in his sleep. He squirmed, trying to escape Berry's steel grip, moaning quietly.

 

Sans jumped, gasping as he felt himself rolled onto his back, whining in confusion, glancing up to find Blueberry hovering above him, his usual star shaped eye lights now hearts.  
Sans's soul skipped a beat.

 

"Hhh... You, You Smell So Good, Comic.." He whined, grinding against Sans's formed magic. He groaned, grabbing onto the sheets.

"W-Wait.." He tried, cut off by Blueberry forcing his tongue into the other. Sans whimpered, squirming beneath the other.

"You Look So Cute, Comic.." Blueberry stared at the other lustfully, making Sans feel self conscious, before yelping as his ankle was grabbed and his femurs where pulled over Blueberry's shoulders.

Blueberry pulled his pajama pants off. "Y-You Smell So Sweet.." Blueberry murmured, grinding against Sans now exposed pussy, the fabric of his pajamas catching his clit.

Sans cried out in alarm, cut off again by Blueberry kissing him. He only whimpered and tried to pull away as he felt magic spike in the room, before hearing a panicked; "sans?"

Sans shook as Blueberry pulled back, stopping his thrusts to stare at Honey. Sans sobbed at the loss of friction, Honey looking between the two of them, his cheekbones flushed orange.

"H-He Smells So Good, Papy.." Blueberry whined, grinding roughly against the other. Sans tried to offer some explanation to Papryus, but all that came out was a high pitched whine at the sudden harsh pressure on his clit. "I Want Him To Be Ours.." Sans's soul stuttered in fear.

Honey caught onto the spike in fear, but continued to creep closer to the two, tilting Sans head back. He pushed his own honey colored tongue past Sans's teeth, relishing  
Sans's choked moan as he struggled to keep up with the other. "fuck comic..." Honey breathed heavily as he pulled back, fully taking in the sight Sans in such a deep heat it set off his own brothers as well. Berry took this time to slip out of his own pajamas, before going back to grinding roughly against Sans, who keened loudly.

"you've been tempting my brother, heh?" Honey grinned at the other, hand moving down to play with Sans pussy, pushing his labia apart with two fingers, watching his brothers blue cock slide between them.

"f-fuck, please-" Sans tried to plead with them to get off, but his mind was hazy with pleasure and he kept gasping for air or moaning instead.

Blueberry huffed, muttering "Language." as Honey continued.

 

"its okay." He tried to soothe the others worries. "we'll make it good for you."

Honey pushed up Sans, making it so he was behind the other, Sans's spine pressed against his sternum. He was bent at a 90 degrees angle between the two, Sans still crying out as Blueberry continued his harsh grinding.

Honey's hand found his slit, pushing a finger past his opening, thrusting slowly, before adding another. Sans's moans grew louder and more desperate and Honey continued, getting rougher with the other until he could get four fingers through, stretching the others magic thoroughly. He then relented, moving away.

"sans?" Papyrus asked softly. His brother looked up, panting.

"be careful. he only has one hp." Blueberry whined, nodding, pressing a kiss against Sans's forehead before his cock into Sans's entrance, slowly breaching his tight walls.

Sans cried out in alarm, pressing his face against Honey's shoulder.

Blue thrust shallowly, moaning. "C-Comic.. O-Oh Stars.."

Honey nodded, pushing down his boxers so only his orange cock showed, before lining himself up next to his brother, causing Sans to jolt in fear.

"n-no!! not both of you please.." He begged. Honey and Blueberry both shushed him gently, kissing away his tears.

"It Will Feel Good, We Promise."

"it's okay comic. we won't hurt you."

Sans relaxed slightly, allowing Honey to thrust the head in, grunting. Sans cried, arching up against them.

Honey grunted, sliding up all the way to the hilt. The two kissed at Sans's collarbone and neck, calming him down slowly.

Honey reached around with one hand, his thumb rubbing small, gently circles at Sans's clit, making him sigh beautifully.

"slow." He reminded Blueberry. The other nodded, thrusting in deep. Sans let out a choked moan, sobbing in pleasure as Berry fell into a rhythm.

"S-So Tight!!" Blueberry gasped, moving faster despite his brother's wishes.

Soon after, Honey began to move as well. Honey and Blueberry groaned at the sensation of rubbing against each other, as Sans shrieked in ectasy, the feeling of the alternating thrusts and Honey beginning to relentlessly thumbing at his clit, proved to be too much-

He sobbed as he came over Blueberry and his own ribcages.

"fuck." Honey growled as he watched Sans become undone. The two brothers lost themselves, thrusting in roughly, hearing Sans cry out, overstimulated, before the two completed inside of Sans.

Blueberry finished first, moaning loudly as his magic filled Sans, kissing the softly crying skeleton afterwards. Honey followed soon after, grunting and hugging the smaller skeleton closer.

The two's magic caused Sans's ecto-stomach to appear, bulging slightly to the two filling him. Honey massaged the flesh gently, pulling out and urging Blue to the same.

The last thing Sans heard before blacking out was Honey cursing quietly and Berry's gasp of amazement, Honey grumbling

 

"we shoulda have worn a condom."

**Notes for the Chapter:**

> Warnings for slight somnophilia, assuming consent, heat induced state, double penetration, slight overstimulation, and some crying! im not sure if this counts as a trigger, but there is hints of pregnancy at the very end, but it's only like two lines of vagueness lolol. i think thats it tho, but tell me if i missed something!  
> i need to work on writing blue lololol  
> If you're wondering, the reason it's so late in swapverse is because the worlds being opposites i image their times are opposite (day in tale is night is swap, and vice versa)


	4. Libido (Underlust)

**Summary for the Chapter:**

> At the end of it, Lust nodded. "interesting.. well, it's always been my dream to fuck my clone!"

**Notes for the Chapter:**

> Alanis_Strife requested lust sans with dubcon, and anon requested overstimulation! i wanna do even more hardcore overstimulation in the future tho so expect more of that (n organism denial, also going to be in a chapter soon! if u dont like overstim im so srry bc all three past chapters had at least a mild form of overstim haha)  
> check end for detailed warnings!

Sans landed in snow with a groan, sitting up to take in his surroundings. He stood slowly, holding his hand out to balance himself against a wall.  
He glanced up, seeing the familiar "Grillby's." Once realizing he was in Snowdin, Sans sighed in relief, and some confusion as he heard faint club music from inside Grillby's. He'd never guess in any timeline Grillbz would play music like that.

He looked to the left, spying the familiar bear that always loitering outside of Grillby's, staring at him intensely.

Sans assumed the other was staring because he just appeared out of nowhere, and began mentally preparing a few excuses as to why, before analyzing the look he was being given further and not seeing confusion, but rather...

Hunger..?

Before Sans could open his mouth to say anything, the door to Grillby's burst open, appearing a version of Sans that was wearing.. a crop top..?

Sans's face heated up at the thought of wearing something like that.

His alternative huffed slightly, mumbling about "grillbz being no fun.." before turning to spot Sans.

This Sans blinked, slowly scanning Sans from top to bottom, then bottom to top, before smirking.

"i would say i haven't seen you around here, but i'm pretty sure i see you every time i look in a mirror." The clone joke made Sans smile slightly, despite his confusion.

This Sans was still staring at him, before looking past to see the bear taking a step closer.

His alternative's eye lights got bigger, like he just realized something, before he grabbed onto Sans's hand.

"what, wha-" Sans didn't have time to question the other before they both blinked away in a shortcut.

 

 

Sans shouted in alarm, clinging to his other as they popped back into existence. The suddenness of the shortcut caught him off guard.

The other Sans laughed. "i didn't know you'd be falling for me that fast." His other winked flirtatiously, before Sans felt himself being pushed gently onto a bed.

"stay there, babe." His other said, before walking out of the room, leaving the door open. Sans sucked in a breath, trying to calm his nerves as he looked around the room.

Despite obvious differences, like how his bed was now shaped into a heart and was so, so soft, this was still Sans's own room. However, instead of regular trash, the floor was littered with different types of underwear, sex toys, condoms, empty and full lube containers. Sans pulled his eyes away from the ground, trying to focus on anything else in the room.

Fortunately, his alternative returned quickly. "if i knew i was having company, i probably would have cleaned up. a bit." His other self sighed, sitting next to Sans on the bed, handing the other a glass of water, which Sans accepted gratefully. "honestly, i have no idea what you were thinking going outside so close to your heat-"

Sans nearly choked on the water. "what??" He stared at the other, who just seemed confused.

His alternative- who Sans was calling Lust for the time being- laughed after a few seconds of analyzing the other. "darling, i can tell if a monster's close to heat, and you both smell and look-" He poked the other's flushed cheekbone. "the part."

"i could have sworn i had another week until..." Sans mumbled, embarrassed by his carelessness. Lust waved his hand in the air.

"don't worry about it. now, i'm more curious as to where you come from, stranger?~" His flirty tone was back.

Sans hesitated, before beginning to explain the basics of how he got to Lust's world. At the end of it, Lust nodded. "interesting.. well, it's always been my dream to fuck my clone!"

Sans froze, cheekbones bright blue. Lust laughed. "i'm teasing! you're so easily flustered!" Sans only chugged the rest of his water in reply.

"you can stay here while we wait your heat out." Lust offered, taking the cup from Sans. "papyrus will be thrilled to have company!"

 

As Lust was leaving to go wash and put the cup away, Sans stopped him with a "wait!"

Lust turned, confusion clear. "what?"

"d-do you have any heat pills i could use..?"

Lust's confusion only deepened. "what pills?"

Sans eye lights grew wider. "do you guys not have heat pills...?"

Lust shrugged. "i don't think so?" Heats weren't a huge deal for monsters down here. Their arousal spiked, sure, and their magic was much more pronounced through smell, but mostly it was just a week of being extra horny, the worst being the first few days.

 

 

Within the next few hours, Lust was quick to learn heats were much more intense for monsters from Sans's time.

Sans reasoned with himself before his heat fully kicked in, that this was because the monsters here built up some immunity after being in a near constant state of heat. He only got so far in his thoughts before his bones burned with need and his soul was pounding too loudly to think. He ended up shedding all of his clothes once the heat became unbearable.

His ecto-pussy was formed, throbbing and dripping. Sans whined, thrusting weekly against an old pillow Lust had given him an hour before. He sobbed, the need for some form of stimulation too much. His soul ached with desire, drowning the house in his scent, letting any willing monster know he was ready-

Sans whined at the sound of the door opening again. Lust was having more trouble than usual controlling himself under urges amplified by Sans's heat, but years of practice weren't for nothing. He handed the other another glass of water, knowing the other must be overheated. "how you feelin', comic?" he had given the other the nickname, before Checking the skeleton, just to make sure he was-

He gasped. "comic! you only have 1 hp??" Sans whimpered at the loud noise, staring at the other with a dazed expression. Part of his brain was yelling at him to try to  
explain his 1 hp was normal, the other screaming to let this Sans fuck him so hard he'd see stars. He sobbed in confusion, not being able to coherently decide which side of his brain was correct.

"p-please.." was the only word he could form, tears forming at the edge of his eye sockets. Lust nodded, pulling the others femurs apart, letting cool air hit Sans's cunt.

Sans near sobbed in relief, throwing his skull back as Lust summoned a purple tongue to run up his slit slowly, stopping to circle his clit generously, before continuing back down. He kissed the others hole softly, mouth returning to gently lap against his clit as Lust thrust a finger into him slowly. Sans moaned loudly as the others tongue returned to his hole, this time pressing his tongue inside the other. Sans gasped for breath in between moaning, letting the other work his tongue in as deep as it could, before pulling out to replace with two fingers, stretching him wide.

Lust pulled away, making Sans cry out. Lust kissed his forehead, thumbing his clit and he reached around to a drawer by his bed. He pulled out a intimidating looking purple dildo, along with a small bullet vibrator and remote.

Lust pulled away completely from Sans, ignoring his sobs of displeasure, to slip a condom over the sex toy. He had cleaned it from last use, but for extra precaution.

He kissed the other again, pressing his ecto-tongue against Sans's, drinking in any sounds the other made. Lust then moved the dildo to push against Sans's entrance.

Sans ground down against the toy impatiently. Lust smirked, shoving the toy to the hilt without much warning, making Sans cry out in relief and pain.

Lust moved the toy in and out of Sans rhythmically, watching in fascination as the other thrust his hips down in time with the toy, keening in satisfaction.

Lust took Sans's distracted moment to press the small bullet vibrator against his clit.

Sans's eye lights shot open at the cold, looking up at Lust in confusion, before screaming as Lust turned on the vibrator, not hesitating to crank it up to the highest setting. Sans came hard around the toy, clenching around the toy. He sobbed, writhing on the bed as he came down from his high, the vibrator still going and Lust not slowing down in thrusting the toy.

Lust chuckled. 

_"comic, you're in for a good time.~"_

 

Sans was crying, hours later spasming on the bed as Lust made him come again. "p-please, it's too much, wai-ait, i-it's too much, AH-!" He cut himself off with a strangled cry as Lust increased the vibrator's intensity, him frequently switching settings to stimulate Sans as much as possible, the toy currently thrusting in deep and slowly. "fuck, f-fuck, fuck, please, please stop.." Sans sobbed, the pain of being stimulated for so long catching up with him fast, tears spilling out from his eye sockets. Lust only smiled at the sight.

"you're so pretty, comic." He sighed breathlessly, kissing the others forehead before thrusting the toy in harder, prepared to make Sans come once more.

**Notes for the Chapter:**

> dubcon, esp in the last few paragraphs! overstimulation to the point of crying, altered mindsets by heat, and crying! lemme know if i forgot something  
> if you're wondering why lust is freaked out, he totally thinks sans was gonna die bc he didnt get relief lol  
> also, lust is very used to monsters with high stamina, which is why it was sorta dubcon at the end  
> i feel like my stories are being a bit repetitive when it comes to structure but ill try to break out of it!  
> thank you to everyone who left a request, kink or au wise!


	5. Bone Appetit (Horrortale)

**Summary for the Chapter:**

> "fortunately for you-" One of Blood's hand's moved to hold down both of his wrists, his hand bigger than the two of them. He was easily able to pin down the other. "i've been wanting a stress reliever."

**Notes for the Chapter:**

> check ending for more detailed warnings!  
> this is pretty hard noncon tho, be warned  
> a ton of ppl requested horrortale, and ^q^ requested knotting along with other stuff, so i decided to add in knotting here bc i thought it fit well enough, lol

Sans popped into existence, grunting as he came into contact with tough ground.

Sans groaned, willing himself to sit up, scanning his surroundings carefully. He recognized his house, which he landed right in front of. So he must still be in Snowdin..?

Before he could find the motivation to stand, he heard a gruff voice behind him;

"hey, doll."

Sans jumped, whipping around to face a- holy fuck. A gigantic version of himself. His eye lights shrunk in disbelief and fear, sight locking onto the caving hole in the others skull. Holy _fuck_ , how wasn't he dusted?

This.. other version of himself brought his one hand up to his unlit socket, digging his index finger into the socket and pulling down in a way that had to have been painful. Sans winced, taking a step back fearfully. His eye lights shrunk as he realized the red stains on his alternative likely wasn't ketchup.

His other chuckled. "you look like you've seen a ghost. well, more like a skeleton, doll."

Sans decided he wasn't going to stick around much longer, turning away from other as he prepared to use whatever magic he had left to teleport away-

He cried out in alarm as he felt someone roughly grab onto his radius, forced to turn around to face the other skeleton again. He couldn't risk the shortcut anymore, the contact with the other making it impossible for Sans to teleport without the other skeleton teleporting alongside him.

_**"w h e r e⠀ d o⠀ y o u⠀ t h i n k⠀ y o u r e⠀ g o i n g ?"** _

Sans's eye lights disappeared, growling a "let me go." before letting out an embarrassing squeaking sound from the surprise of being lifted and placed over the others shoulder.

Sans gasped, realizing just how huge the other Sans is in comparison. "put me the fuck down!" he seethed, starting to panic and attempting to struggle against the arm holding him against the shoulder.

His other self laughed.

"i like this one."

 

 

Sans yelped as he was roughly thrown against the floor of this Sans's- who he's calling Blood- house, but more specifically, the basement lab.

Sans's eyes sockets widened, sitting up, but before he could even consider teleporting, Blood was back on him, forcing Sans down on his spine.

"i know who you are." Blood drawled, threateningly. "and i know how you got here. it's the machine, right?" Sans's eye lights shrunk, attempting to crane his neck an unhealthy amount to spot the machine.

Blood laughed dryly, sitting up so Sans could scramble onto his ribcage, looking up hopefully to find-

A machine, sparking and half destroyed. Sans's eye lights extinguished again. He heard Blood's chuckle behind him. "ya ain't getting home anytime soon, doll."

"i really should just dust you right here. we both know how easy that would be."

Sans froze as he felt someone much larger than him press against his spine, forcing his ribcage against the floor.

"fortunately for you-" One of Blood's hand's moved to hold down both of his wrists, his hand bigger than the two of them. He was easily able to pin down the other. "i've been wanting a stress reliever."

Sans jerked as he felt Blood's other hand reach to his pelvis, forcing his spine to curve so he could press Sans's tailbone to the front of Blood's pelvis without Sans's ribcage moving from the floor.

Sans shuddered, moving his knee to kick Blood's femur. Blood's grip on his wrists loosened from surprise, just enough for Sans to slip out from underneath the other.

He pushed himself away from Blood, attempting to stand up and run, or maybe even gather enough focus to shortcut away or use an attack-

Sans cried out as his body felt burning hot suddenly, his soul aching in desire. He tripped over his own feet, landing hard on his spine once more. He breathed heavily, trying to figure out why his magic suddenly acted like this and holy fuck why his magic trying it's damnedest to form around his pelvis-

Sans's spine hit a wall as he continued to back up, sobbing in fear. He tried desperately to stop hyperventilating and to just think clearly, blinking as he stared at the monster before him.

Blood was staring at Sans, his grin widening as he smelled the other's heat, thick in the air. "doll, you're giving me mixed signals here."

 

Sans was crying, his spine being pressed uncomfortably against the cold wall of his small lab, Blood holding him up effortlessly by his thighs, face pressed against his dripping cunt.

"you look absolutely delicious, doll."

Sans gasped, letting out broken moans and pleads for the other to stop as he felt sharp teeth press against his clit, the other slowly moving down until he reached Sans's entrance.

Blood summoned his tongue, wasting no time to get a taste of Sans.

His other sobbed, his hands scraping against the top of Blood's skull, being careful not to get too close to the gaping hole. After just a few minutes of Blood exploring Sans's insides with his tongue, he pulled away, pulling Sans against his still clothed chest, forcing the naked skeleton to cling to his shirt to not loose balance.

Blood licked the side of Sans's neck, leaving a trail of both his magic and Sans's magic in it's wake.

Sans risked a glance down as he felt Blood shift all of his weight to one arm, panic seizing his soul as Blood pulled down his shorts just enough to reveal his massive cock. His eye lights shrank, whimpering. 

"i-it won't fit.." Sans trembled, jumping as Blood only grunted slightly in acknowledgement, readjusting Sans to brush his sock against Sans's sorely unprepared pussy.

Sans's soul stuttered when he realized Blood wasn't stopping, hand shooting out to grab onto his wrist. "y-you'll break me, it's not going to fit it's too big.." He pleaded, fat tears running down his cheekbones.

 

Blood growled in warning, but paused. Sans near sobbed in relief, letting go of Blood's wrist.

He screamed as Blood turned him around roughly, knocking any breath out of Sans. He choked on another scream as Blood thrust in his tight entrance, burying himself to the hilt immediately.

His cunt stretched, trying to accommodate the massive size of the other. Tears continued to spill out from Sans's eye socket as he groaned, trying to flinch away as his ribs scraped uncomfortably against the wall with every powerful thrust from Blood. He was stopped short by Blood's own ribcage.

**"you think you have any control in this situation, doll? you're in my timeline now, my personal fucktoy."** His alternative growled against his skull. **"not that you wouldn't be okay with this, considering you went into heat after me just pinning you down. you really wanted to-"** Sans shrieked in agony at a particularly harsh thrust. **"-jump my bones, didn't you?"** his alternative laughed.

**"you're ticket back home is destroyed. you won't last a day here with one one hp. so you've got no choice but to shut up and take my magic like the good little bitch you are."**

Sans cried as he was suddenly lifted off Blood's cock, only to be thrown back down on the floor. Sans was to weak to try to sit up, breathing heavily as he tried to focus on not loosing his one hp.

 

It didn't take long for Blood to pull his femurs apart and start pounding into the smaller skeleton again.

Blood was biting his collarbone, his thumb scraping against Sans's clit roughly.

That's all it took for Sans to come, clenching against Blood's cock as he screamed, spine arching. It wasn't soon after that Blood groaned and thrust his pelvis forward.

Sans's eye lights widened at the unmistakable feeling of Blood's cock getting thicker at the base, shouting in discomfort and attempting to scramble away.

He was grabbed and pushed down to take Blood's now growing knot, screaming as he heard Blood mutter a _**"take it."**_ darkly against his cheekbones, before Blood's knot inflated fully, locking the two together.

 

Sans sobbed as the other's magic filled him to the point of his ecto-stomach forming and bulging forward with the excess of magic. Blood only hummed lowly, but contently above the other, pulling out once his knot deflated enough, lifting up his femurs to watch his magic slowly drip out of Sans's stretched cunt, before placing him back on the floor to push lightly against his distended stomach, smirking as the other whined from discomfort.

"maybe if we're lucky, we'll have a few baby bones around too." Blood joked, picking up Sans to leave the lab and find his new pet some restraints.

Sans didn't have the energy to cry any harder.

**Notes for the Chapter:**

> heavy noncon, nonconsensual touching, rough sex, unprepared sex, wall sex, treating someone like a sex toy, degradation, knotting (bc kinks lol), size differences, monster cocks and more crying!  
> lemme know if i forgot something!


	6. Obedience Training (Swapfell)

**Summary for the Chapter:**

> "MUTT, EAT." He heard Raspberry's smug voice from behind him, whining at his femurs where pulled forcefully apart, his cunt on full display. Mutt let out a low growl of approval, staring at Sans's pussy with hearts in his eyes.

**Notes for the Chapter:**

> check end for more detailed warnings!  
> sorry for the lack of updates, i got busyy~ !!  
> hey y'all, i very slightly edited my last chapter, just fixed some errors and flowing problems, not a huge difference  
> but the real question is, should i continue to post daily when i can, or should i try every other day to take more time to edit and fix my work?  
> you deciiiide

Sans grunted, the upper apart of his body knocking against something hard, his lower half on something soft. He moved to take in his surroundings, and-

"WHAT THE FUCK??"

Was promptly shoved onto carpet.

Sans let out a small noise of pain, shakily standing up. "WHO THE FUCK ARE YOU??" He looked up to find a very pissed off version of himself, glaring at him from the edge of his bed.

Oh.

"i..." Sans's fumbled over his words, trying to think of something to say. Before he could organize his thoughts, he felt the familiar spark of magic in the air.

He then dodged a jagged bone, one that was aimed right at his head. Sans gasped, moving to spot- Papyrus?- Dodging another bone attack. His back hit a wall, before a blue bone attack jutted out from the wall, forcing Sans to stay still rather than risk moving. His eye lights shrunk as multiple more jagged bones appears before him, aimed at him. He closed his eye sockets, preparing for his dusting-

"MUTT, DOWN!!" Sans's eye lights shot open to his alternative, the smaller skeleton now completely off of his bed, standing in a star patterned tank top and black shorts.

The Papyrus raised a brow bone, but dispelled the bones, only leaving the blue attack pinning Sans's to the wall.

"of course, m'lord." He mumbled, bowing slightly. Sans's eye sockets widened further in confusion. 

 

Sans's alternative, who Sans decided to call "Raspberry," stared at him, looking him up and down. Sans nearly jumped, calming himself last minute to avoid dusting as his other self walked towards him, running a bony hand over his skull and eye socket, tracing where the scar would be mirrored from Raspberry's self.

"he looks like you, m'lord."

"I CAN FUCKING SEE THAT." Rasp growled, turning to the Papyrus.

"AND WE ARE GOING TO FIND OUT WHY. PAPS, BRING HIM DOWN TO THE SHED. I'LL JOIN YOU TWO SOON." The Papyrus nodded, the blue bone holding Sans disappearing.

Sans let out a sigh of relief, flinching as this Papyrus; Whom Sans is calling "Mutt" for now- grabbed onto his ulna.

"m'lord has a few questions for you." Was all he explained before the two teleported away.

 

Sans pushed away from the other as they snapped back into existence, landing hard on the floor. Mutt chuckled at his reaction.

Sans suddenly felt very small as Mutt stared down at him.

 

He flinched again as the door burst open after a moment or so of him and Mutt staring at each other. Mutt only turned, staying perfectly deadpan.

Rasp had entered, now wearing black armor with a purple bandana tied around his neck. 

Raspberry's eye lights shifted to Sans. Sans felt himself being "CHECKED" Rasp's brow bones furrowed, glaring at the other.

"YET, HE HAS THE SAME STATS AS YOU.." He addresses Mutt, who "CHECKED" Sans next.

 

"i may, have an explanation, m'lord." Mutt hummed. Sans stared at the two in bewilderment.

Raspberry's eye light's never stopped studying Sans's body, but a small noise of acknowledgement let Mutt know Rasp had heard him, so he pressed forward.

 

Mutt went on to explain the machine in the lab, what it's primary function is, and his theory that Sans came through the machine from his own timeline. Sans stared in absolute wonderment and anxiety as the other easily explained this all to his brother. He couldn't imagine telling his own brother about anything that has to do with timelines. This, and Mutt just being treated like a dog, led Sans to silently wonder about their relationship.

"IS THIS ALL TRUE?" Raspberry yelled, snapping Sans out of his thoughts. Sans nodded, dazed by the whole ordeal. Raspberry scoffed, muttering about how he thought Mutt was fucking with him, before pausing.

 

"WHAT THE FUCK IS THAT SMELL?" Rasp brow bones raised, arms crossing. Mutt's eye lights traveled to Sans.

Sans was too distracted by his soul, which felt burning hot. He made a noise of discomfort, curling in on himself as his bones heated up and his ecto-pussy formed, despite Sans's wishes.

He was swearing at himself, whining as another stab of arousal struck his soul, making his body shudder with need.

 

Rasp sneered at the other, before snapping his fingers. Mutt instantly became more alert, awaiting his lord's command.

 

"MUTT, SERVICE THIS VERMIN. WE CAN'T HAVE HIM ATTRACTING ATTENTION BY LETTING THE ENTIRE UNDERGROUND KNOW HE WANTS TO BE FUCKED."

Sans whined louder at his cruel words. Mutt nodded, mumbling a "of course, my lord."

Mutt knelt down near the other, raising his brow bones when Sans frantically moved away. "stay away from me." Sans growled, meaning too sound more intimidating. Judging by Mutt's smirk, he only succeeded in amusing the other as his voice had a high pitch to it from fear.

 

"He's not being cooperative." Mutt said dryly, turning to Raspberry. Rasp glowered from where he was now sitting, having pulled up a chair after giving Mutt a command. 

"YOU ARE MAKING THIS MUCH MORE DIFFICULT THAN IT NEEDS TO BE." He snarled, pulling the bandana from his neck, moving to walk behind Sans.

Sans froze, feeling very cornered as the two's eyes bore into him.

He shrieked as Mutt grabbed onto his wrists, Rasp pulling his bandana over the others eyes before tying it tightly. He jerked, trying to dislodge either skeleton.

He heard Rasp huff, telling Mutt to hold on, before he walked away. Sans cried out, soul pounding as he tried to listen for anything to clue him in on where his alternative walked off to, trying to jerk away from Mutt's tight hold. He heard footsteps return, getting closer to him. Sans gasped sharply as his jacket was tugged off, then his shirt. Both were yanked off too quickly for him to react, his wrists behind held down again as he was lifted and his shorts and shoes quickly shoved off.

Sans jumped as he felt his arms being forced behind him back, feeling restraints tighten around his wrists. He pulled away as he felt something brush against his spine. Sans heard a low growl, before he was roughly handled back into place, two hands on his pelvis keeping in him place as whatever material binding his wrists together was also tied to his spine, making his arms stretch uncomfortably and left no room to move his arms. He shuddered, feeling the ghost of a hand brush down his sensitive ribs, making Sans moan softly.

He heard a quiet chuckle, Sans's feeling his face flush blue at the attention and how his body reacted to it.

He froze, shaking as the body behind him moved away.

 

He tensed as the same hands glided across his plump pussy, shivering as his lips where spread and magic trickled down from them, his cunt throbbing.

 

Sans opened his mouth to say something, but choked as something was shoved into his mouth. He moaned, confused, feeling something push down against his tongue. He realized he was being forced to suck on phalanges, the bone scraping roughly against his ecto-tongue.

He shivered, tears forming behind the blind fold as he felt the fingers slip out of his mouth, magic connected them for a few seconds more but the strings disconnected. He heard people talking in the background, but he couldn't focus on the words.

He flinched at the feeling of something pushing teasingly against his clit, thrusting up against the touch without thinking. He cried out in disdain as the friction went away, hearing faint laughter in the background.

 

Sans attempted to focus on the conversation happening around him, but his focus was lost as two fingers were shoved up his entrance. He cried out, jerking roughly. Sans didn't know if it was to get away from the fingers or to get more of them.

He moaned brokenly, mewling from the pleasure of the bone-y fingers, reaching deep inside him and pressing against his walls. He thrust back down onto the fingers, urging them to go faster as he felt his release building-

Sans sobbed as they pulled away from him, letting out a broken plea. He thrust into the air a few times, completely thrown off from being so close to orgasming and then having it ripped away from him.

He gasped loudly as he felt a body press against him, his blindfold being tugged up from his eyes. He blinked, eye lights hazily looking around the room. They finally landed on Mutt, who was drooling and on his knees before Sans. He flushed a brighter blue at how the Papyrus stared at him hungrily, his own eye lights clouded with lust.

"MUTT, _EAT._ " He heard Raspberry's smug voice from behind him, whining as his femurs where pulled forcefully apart, his cunt on full display. Mutt let out a low growl of approval, staring at Sans's pussy with hearts in his eyes.

Rasp smirked against Sans's neck as Mutt moved to lay down on his back, Rasp simultaneously moving to pick up Sans from where he was sitting. 

"wha-?" Sans whimpered, dazed, feeling himself being re-positioned. He let out another noise of confusion, before moaning loudly as he felt something grab onto his femurs and pull him down, and something wet pushed insistently against his pussy.

Sans choked on another moan, looking down to find he had been re-positioned over Mutt's head, the one below him eagerly licking at his cunt, greedily gulping down any magic that spilled from Sans.

Sans cried out, feeling someone grab at his skull insistently and another tongue push past his teeth, Sans panting by the time they pulled away. He found a grinning Raspberry above him, Rasp reaching behind him to undo the knot and free Sans's hands. He moaned, gasping as Mutt's tongue finally breached him, the one below him sighing in bliss.

 

Sans bucked down against the other, his thoughts becoming muddled as he moaned and pleaded endlessly. He had no idea ecto-tongues could form to be so long.

Sans keened, hand shooting out to steady himself against Rasp. Fuck, he was so close!

"MUTT, DOWN." Rasp growled. Mutt growled in displeasure, but pulled himself away from the blue alternative. Sans gasped in shock, falling against Raspberry in shock.

"f-fuck.."

He whined as Raspberry pulled him forward and off of Mutt completely. His SOUL burned, he needed to cum!-

Sans yelled in shock as he felt Raspberry's cock enter him, Rasp groaning. "FUCK, YOU ARE TIGHT." He shot a glare at Mutt, who watched the two in absolute adoration. "GET OVER HERE."

Mutt happily obliged, moving to the shaking Sans, who was grinding down desperately against Rasp's cock. "JOIN ME, BROTHER." Rasp purred, invitingly spreading Sans's lips further, making him whine loudly at the stretch.

Mutt nodded, lining up his own cock against Sans's cunt, pushing forward slowly but without hesitation. Sans cried out in alarm, feeling himself being stretched.

Mutt and Rasp thrust brutally, not allowing Sans to adjust, Rasp grinning and hissing to Sans about how he was made to be another one of the Malevolent Sans's pets, Mutt letting out a noise of agreement every so minutes.

It didn't take long for Mutt to slam into Sans roughly, gasping a "m'lord, may i?" before releasing inside of Sans at Raspberry's nod. Sans cried out, clutching Rasp's ribs.

Raspberry gasped, thrusting into Sans and pulling Mutt in by his collar for a deep kiss, before also cumming deep inside Sans.

As the two got lost quickly in their kiss, Sans sobbed, hiccuping as he was robbed of another orgasm, trying to grind down on nothing.

Rasp grinned. "YOU HAVEN'T EARNED A RELEASE YET, PUPPY."

 

Sans was writhing on the floor an hour later, begging for Rasp to let him come as Mutt switched between pressing a vibrating dildo against his clit, fucking Sans with the dildo, or using his tongue to bring the other to near completion.

Raspberry watched cruelly from a chair nearby, enjoying seeing his pets play with one another. He routinely praised Mutt for helping "PUPPY" through his heat, calling him a good dog. Mutt reacted positively to the praise, always pulling away from Sans when Rasp ordered it, even if Sans's cries of pain hurt him, and doing his best to please Raspberry by drawing the most lewd moans and gasps from Sans.

Finally, Sans broke down, thrusting into the air, crying out- 

**_"please master!! please let me come!! i'll be a good dog!!! please!!"_**

Rasp grinned, nodding to Mutt. "ALL YOU HAD TO DO WAS ASK." Rasp purred as Mutt pressed the vibrator against Sans's clit roughly, making him see white and cry out in bliss as he finally orgasmed.

 

When Sans had finally calmed down, he opened his eye sockets to find Raspberry snapping a collar around his neck, Mutt sound asleep across his lap.

Rasp stared at his two pets, grinning, petting Sans's head, who whimpered and leaned into the touch.

"GOOD PUPPY."

**Notes for the Chapter:**

> non con! pet.. play? i mean, not really, but the element of it is kinda there. eating out, orgasm denial, some fighting, blindfolding, mind break at the very end, restraints, and slight praise kink! and some more crying, but that goes without saying i think by now  
> my version of swapfell is whatever rasp wants to know, mutt will tell him. if rasp wants to hear about the resets because he somehow found out, mutt will shrug and tell him. his bro can handle it, and its likely it will be reset and he'll forget about it anyways. these two trust each other to always be truthful.  
> i'm thinkin of making a few continuations and a very, very special ~alternative~ chapter to how Underlust could have turned out. im bringing the b i g guns for that one. and then i'll continue with sans traveling to different au's! i just need a break to continue these stories before the load becomes too big  
> Requests from this!  
> Cosmo wanted blindfolding (i'm sorry i forgot to reread the comment and didn't see the loss of hearing, but i edited it so sans didn't really hear much anyways from his daze so i hope it's alright!) more double penetration, and i know i've been doin' cunnilingus a lot, but i couldn't resist the idea of horror sans wanting to eat sans out, and rasp commanding mutt to eat like a dog lol. it's my fucked up humor, i guess.  
> a lot of people have been asking for swapfell, which i happily wrote.  
> anon requested orgasm denial! i loved adding that in lolol.. you guys seem to just know all my favorite kinks..  
> also, this is currently my longest chapter! just wanted to share  
> pls comment if i should update every day or every other day.. i'd love to know.. thnks <3 lov u all


	7. Collared (UF Sequel)

**Summary for the Chapter:**

> Nine months after Sans appears in the Underfell universe.

**Notes for the Chapter:**

> i'm not dead just yet! hit a busy spot, i'll be back on schedule soon<3 lov u all  
> more detailed warnings n stuff at end!

It has been nine months and counting since Sans fell into Red's universe.

It has been nine months and counting since his forced soul bond with the two brothers.

It has been nine months and counting since he has seen his Papyrus.

 

The brothers- _This world's version of Papyrus demanding to be called Boss by the two Sanses, and Red asking for the other to call him multiple names while behind the bedroom, his favorites seeming to be "Master," "Sir," and "Daddy-"_ both took the anniversary of their "soulmatesmanship" very seriously.

It was one of the rare time Sans was allowed outside of their house, both too nervous to let him be outside with his one HP, even if the two had made it perfectly clear to the outside world Sans wasn't on the market.

From the red collar adorning his neck, _(the leather was crimson and enhanced by both Red and Boss's magic, a metal blue upside-down heart hung from the D-ring on the collar. Red said "the bit of blue brings out yer eyes.")_ to _both Red and Boss taking him in the middle of Snowdin, telling him that they had to 'properly' claim him for 'everyone too see,' baring his weakened soul splashed with different shades of red for all of the Underground to see, growling at citizens who got too close or pointedly biting his clavicle at particularly hungry stares. Sans crying from being so exposed, from how Boss and Red's rough thrusting and biting was at ends with their kind and reassuring whispers to try to calm him down from his panicking-_

It.. was clear Sans was not for public consumption.

 

Red was much more prone to taking Sans outside, rather than Boss. Red would carry Sans everywhere, bring him to his sentry stations, _(the feeling of Red pounding into his oversensitive cunt while gagging on Boss's load, the Papyrus forcing him to summon an ecto-tongue and throat to take his cock to the hilt and swallow completely, screaming in pure agony as his soul was forcefully invaded twice in a day by a monster he didn't even know-)_ toying and showing off Sans proudly, having Sans sit in his lap at Grillby's, laughing as he hid his face in Red's jacket from pure embarrassment. 

 

Red was very, very fond of teasing Sans in public, setting and attempting to break records of how many times he could make Sans cum before they where caught or had to return home. His record was currently 8. _(Grillby shooting them threatening looks if Sans got to loud while Red played with his pussy underneath the bar counter, Red randomly spiking the intensity of the vibrator he would sometimes strap to Sans, making the smaller jump and cough to cover a moan, Boss finding the two underneath Red's Hotland sentry station, Sans begging the other to s̶t̶o̶p̶,̶ ̶s̶t̶o̶p̶s̶t̶o̶p̶s̶t̶o̶p̶ ̶p̶l̶e̶a̶s̶e̶ ̶s̶t̶o̶p̶ slow down while Red grinned against his cunt, looking up at Boss invitingly. Later, Red had been punished for slacking off at work and endangering Sans by bringing him all the way out to Hotland, and rewarding Sans for having some 'sense' in the situation.)_

 

Usually, Sans was ordered to stay inside the house of the two. He had free reign over the place, only being locked out entirely from the basement lab. Sans even checked around Red's room but he could never find the key.

When Sans went into heat, neither brother went to their work posts. They stayed home, fucking Sans throughout regular intervals, and made sure the other ate and drank enough to make up for his lost magic while in heat. When either or both brothers went into heat, they tied Sans's legs up to a spreader bar, gagged him with an "O" ring, and kept the him in who ever was going through their heats room. The brothers would appear every once in a while for a quick fuck, just enough to tide their heat over during the day until they could get home and show Sans just how much they appreciated him helping them through their heats.  
If there was just one in heat, the other brother would check on Sans to make sure he was holding up well. If both Boss and Red were in heat, he would be taken all around the house, and once whichever brother finished it's likely he would just be dropped on the floor while the other continued on with their day. Any form of aftercare only came after their heats had passed.

 

Boss was much more comfortable showing affection to Sans at home, affectionately calling the other "Pet" and "Love," cooking him things to set up semi romantic dates.

Sans cried when Boss cooked for him the first time, because it reminded him so much of his own Papyrus. Boss had held him in his lap and let Sans cry it out, apparently flattered as he thought the crying was from gratitude.

Boss had Sans sleep with him, attempting to calm the other down during his nightmares. It only took a week for Red to join them in bed, Boss apprehensive at first but eventually letting the other sleep with the two.

 

Which lead to Sans's current situation.

He was used to waking up in between the two skeletons, usually softly awakened by Boss's gentle rubbing and whispering "Wake up, My Love." To him, or Red kissing over his face, mumbling a "g'mornin', sweetheart." Before getting up for the day.

Sans gasped as he awoke to his femur being pulled up to his side, panicking as he felt a hand press against his teeth.

"shh, babe." He heard Red whisper in his ear. "don't wake up boss." Sans uttered a low whine as he felt his pajama pants be pulled down halfway, feeling Red's cock rub against his already forming cunt. Sans weakly wondered how long they've been doing this he just formed his ecto-pussy on instinct alone. He felt sick at the thought.

Sans shook on the bed, gripping the pillow he was sharing with Red, shutting his eye sockets to avoid looking at Boss's sleeping face, just inches away from him.

"yer so good, sweetheart." Red rumbled, grinning against Sans neck as he continued to grind against his dripping cunt. "so fuckin' wet for me."

"And When Were You Going To Wake Me Up?" Sans squawked indignantly at the low growl of Boss, Red's eye light's shooting up to study his expression. Red grimaced, sweat beading on his skull.

"happy anniversary..?"

Boss grumbled, but his eyes were on Sans, who was flushed blue at the attention.

"What Would You Want Us To Do For Our Anniversary, Pet?" Boss questioned, brow bones raised.

Sans squeaked, face lighting up even further. He felt Red smirk widen, his pants now pulled completely off his legs, leaving him just in an oversized shirt.  
"yea, sweetheart, what do ya want us to do?"

 

Sans froze, staring at Boss nervously. "a-anything?"

"of course." Red kissed against his neck. Boss nodded in agreement.

Sans clenched his hands against the pillow. "can i... can i see my original papyrus again, please?"

Sans's SOUL skipped a beat as the air tensed, Red's slow grinding halting completely, Boss's eye lights boring into his own.

"ya what?" Sans trembled at Red's tone.

"i-i'm sorry, that's stupid of me too-"

"Okay."

Both Sans's stared up at Boss in confusion and disbelief, the taller skeleton sitting up and standing up from the bed. "Pet, Come Here."

He hesitated, but Red pulled away from the other, leaving Sans with no choice but to shakily crawl towards Boss.

Boss picked the other up with ease. "Sans, Is The Machine Operable?"

"boss, that's our-"

"We Are Going To Make It Clear That Our Soulmate Will Not Be Returning Anytime Soon." Sans froze, his eye lights disappearing at the tone of Boss's voice.

Red's smirk returned, before he teleported away, returning seconds later with a familiar key. "let's get to it then."

 

"p-please stop.." Sans whimpered, forcefully help up by Boss's fingers on his collar, his femurs spread to show off his still formed ecto-pussy. Sans near sobbed at the familiar sound of a camera click.

Boss ignored him, but Red indulged. "hey, ya said ya wanted to see yer papyrus, right? this is yer ticket." He chuckled, watching the picture print out from the printer on the counter of the lab.

"i-i'll do anything, don't show p-papyrus these, please.." Sans was pleading, his body racked with sobs. Red tapped his chin thoughtfully, smirking.

"what do ya think, boss?"

Boss hummed, sitting behind Sans and lining up his thick, red cock against Sans's cunt, grinning as Sans cried out in fear as Boss summoned his red stained soul.

"Get A Good Angle Of This."

Boss clutched his soul in one hand and breached Sans's entrance with one swift motion upwards, the camera clicking again as tears streamed down from Sans's face.

 

Red was smiling mischievously afterwards, Sans's sitting on his lap, shivering. Red flipped through the photo's on the camera's storage as Boss gathered up the printed versions. Red watched Boss's cum leak out of Sans's pussy slowly, the others tear stained cheekbones pushed against Red's pajama shirt.

"this one's my favorite." Red teased, watching Sans turn away from the photo. It was Sans at the point of climax, eye lights rolling up to the back of his skull, his bonded SOUL visible through Boss's splayed fingers, his other hand clearly thumbing Sans's clit as he was in the middle of another merciless thrust. "you look so damn irresistible in it." Red nuzzled against his soulmate affectionately.

"I Have Gathered All Usable Photos." Boss declared, searching through the machine's setting. "These Coordinates Are Correct, Right?"

"yea boss. i double checked the universe beforehand." Red nodded, petting Sans's skull.

Boss smiled, pushing the box of lewd photo's with his soulmate through the portal. Usually, he would be very against showing off his soulmate at his most vulnerable, but this was necessary for both his soulmates and his soulmates old companions lessons.

The machine whirred to life, before accepting the box and shutting down. Red whistled lowly, pressing a skeleton kiss against the smaller, sobbing skeleton's skull.

"now you really will be ours forever, sweetheart.~"

**Notes for the Chapter:**

> noncon, public sex, somnophilia, public claiming, possessiveness, taking pictures of other without consent(?), collars, dom/sub dynamics, master/pet dynamics, unhealthy relationships, sexual conditioning and even more crying!  
> also uf's think their plan at the end there will work bc in uf u just gotta "claim" ur soulmate publicly so they were like "haha same concept."  
> lemme know if i forgot a warning!  
> i don't know how many chapter's im gonna do, i'm just rolling rn. i am also planning another story, so be on the lookout!  
> thanks for reading!!


	8. Overindulgence (US Sequel)

**Summary for the Chapter:**

> Two months after Sans appears in the Underswap universe.

**Notes for the Chapter:**

> not my best but not my absolute worst..?  
> it's a bit shorter than most of my chapters. it's just honey trying his best to push away guilty feelings and failing and sans being depressed  
> more detailed warnings at end!

Honey CHECKed Comic, cringing at the stats.

When he first CHECKed the other, his stats read:

 

***SANS**  
***1 HP**  
***1 ATK**  
***1 DEF**  
***Comes from another world.**

Now, Comic's stats read:

***SANS**  
***1 HP**  
***1 ATK**  
***1 DEF**  
***Is pregnant with your child.**  
***Really wants to go home.**

 

Honey sighed, shifting closer to the other, trying to ignore how he flinched away.

"hon, i can't let you do too much, much less jump timelines, with a SOULing.."

He didn't believe it at first either, Blueberry summoning the SOUL from the unconscious Comic, gasping in wonder at the small, purple color in the middle of his SOUL.

There was no doubt about it- Somehow, either Berry's or his own magic reached Comic's SOUL, and a tiny SOUL formed within him. Honey supposed with the "PERSEVERANCE" trait, it wasn't too surprising the SOUL, well, persisted.

 

When Comic had woken up, Berry couldn't contain his excitement and told Comic he was going to be a dad. This, of course, lead to Comic panicking quite badly, only worsening as he pulled out his own SOUL to see for himself.

Honey had ushered Blueberry out of the room while he calmed Sans down.

Honey didn't know how long the smaller cried into his hoodie, rubbing his back and shushing him quietly.

When his words became coherent again, Comic only begged for one thing-

"i need to get back home."

 

Near daily since then, Comic had asked either one for the machine to be fixed and for him to be able to return home. Both, of course, refused, Blueberry saying the child would want to meet their dads, and Honey not wanting to endanger the SOULing by sending Comic through a machine he barely knew how to operate.

 

"you can't understand how this feels." Honey grimaced. Comic were completely dry, turned away from the taller skeleton on his bed. Honey let him stay in his room, actually cleaning up his room and fixing his bed at the realization an expecting mother would be staying in his room.

"i know this isn't.." Honey paused, choosing his words carefully. "ideal, for you, but with only one HoPe, losing a child could kill you." Honey said softly, knowing just how fragile one HoPe is. He's dealt with this for the last few years of his life.

 

"i don't. care." Honey froze at the animosity of his voice. Comic turned to him, blinking tears out of his eye sockets.

"i just want to see my brother again." Comic finally sobbed out, letting himself fall against Honey.

Honey brought his arms around him, rocking them slowly. He stared down at this other Sans, dumbstruck.

He thought of his own Sans stuck in another universe.

He thought of his own Sans stuck, pregnant, in another universe.

 

Honey tried to not let the guilt of doing this to Comic crush him.

 

Comic has thankfully calmed down after a few minutes, but Honey became acutely aware of something else.

He could feel the heat radiating off Comic.

The pregnancy had made Comic's sex drive shoot up, but usually his own brother happily serviced the other Sans until he was satisfied. His Sans was still out training.

Honey carefully lifted up Comic, letting him rest against his thigh. Comic froze, phalanges clutching Honey's hoodie, before he slowly began to rock against the other.

Honey heard Comic sigh in relief, his rocking becoming more erratic, desperate for friction.

"can i..?" Honey mumbled. Comic nodded, tears prickling at the sides of his eye sockets once more.

Honey slipped his fingers beneath Comic's shorts, teasing his clit. Comic let out a small moan, pressing harder against Honey's rib cage.

"i hate you." He mumbled. Honey began to work more vigorously.

"i know."

"i don't.." Comic choked on his own words as Honey slipped a finger into him, pushing against his walls.

 

"let me help you forget about it for a while." Honey hushed, pushing a second finger against his entrance, his thumb still rubbing circles against his clit.

Comic let out broken sob as he came, stuttering against Honey, who pulled away immediately and stared at the other.

"i'll go get you new shorts." he mumbled, laying Comic down on his bed again.

 

"i didn't want any of this."

Honey froze at the door at Comic's quiet confession. He turned back to find Comic curled up on his bed, facing away from him.

"... i'm sorry."

Honey closed the door, knowing "sorry" wouldn't help.

**Notes for the Chapter:**

> Pregnancy, Unwanted pregnancy, grinding, clothed grinding, guilt. Let me know if i forgot something bc im not really sure how to tag warnings on this!  
> i may come back and edit this later.. idk. but i still kinda like how i wrote honey here?? idk it's late.


	9. Endearment (UF Continuation)

**Summary for the Chapter:**

> The human hadn't been back in over three whole months now, Red figured they gave up saving his world for good-
> 
> "no." He thought, glaring at the general direction of the human. "they just finally learned to play by the rules."

**Notes for the Chapter:**

> hey y'all. have some more underfell <3 (check end if ur curious why i'm posting another uf chapter..)  
> i'm going to be posting an alternative to the underlust chapter tomorrow, and it's going to hopefully cover the kinks of those who requested and have waited a while. sorry, i really am trying to keep this story updating quickly and consistently, so if you've been waiting a while, i'll get to you. don't worry!  
> check end for more detailed warning and more plans of mine!

Red grinned at his Lil' Blue, who had fallen asleep against his rib cage. The two were currently at Red's sentry station, the one outside of the ruins.

The larger toyed with the collar around Blue's neck, still high off the idea that he finally claimed someone for his- and his brothers- own.

God, and was Lil' Blue perfect, and theirs.

Red's hand slipped down to slowly curl around one of Blue's ribs, the thought of **"mine."** dancing in his head as he fully took in how Sans looked.

Wrapped in one of Red's old jackets that was way too big for him, with no undershirt, and adorning a small black skirt. (That was Boss's idea, Red had teased him about wanting "easy access.")

His shit-eating grin only grew as Blue jolted awake, gasping, one hand coming to clutch at where Red's hand was phalanges where bent around his ribs, which was a particularly sensitive spot for his Lil' Blue. Red kissed the top of his skull, drinking in small whines as he continued to tease Blue, wondering if he could push it far enough that Blue would actually form his ecto-breasts for Red to play with-

He stopped suddenly, a faint sound catching his attention.

He ignored Blue pushing his hand away, turning to stare at the direction of the Ruins.

"blue, stay here." He placed Blue below the sentry station, watching him curl up on the corner of the ground, nodding in satisfaction before teleporting away with a snap of magic.

 

He took a shortcut to the Ruins door, eye lights shrinking as he found it wedged open.

Red shortcut again, landing on an already broken stick. He stared ahead, seeing a small human, a rubber knife in their hand, and dust covering their clothes and  
hair.

"fuck-" Red cursed silently, teleporting a third time to get back to his sentry station. The human hadn't been back in over three whole months now, Red figured they gave up saving his world for good-

 _"no."_ He thought, glaring at the general direction of the human. _"they just finally learned to play by the rules."_

Kill or be killed. That's how it was in his world.

Of course, they only figured this out after Red found something that made him happy, made his brother happy, and now they were here to take away something that was **_mine, only mine-_**

He was brought out of his thoughts by a shaky voice.

"sir..?"

 

Red sighed. He couldn't get lost in thought now. The human was going to make it to his sentry station soon. He turned to Bue, who stared up at him, eye lights wide.

"hold on tight, baby." Red mumbled, grabbing onto Blue, who squeaked in surprise, before teleporting.

 

The two landed on Red's bed, Red standing as Blue tried to get his bearings back.

"sweetheart, i need yer to stay here a while, okay? don't even leave my room." He kissed the top of his soulmates head. "be good, blue." The underlying threat of what would happen if he wasn't lead to Blue nodding slowly.

"good. love ya babe."

 

He made his final shortcut, back to his sentry station, just in time to see his brother stomping towards them. He side-eyed the human, before snarling;

"quick, behind that conveniently-shaped boulder."

 

 

Red had one hope- that the human wasn't going to kill his brother.

If they were going for Boss being king, Red could live with being royalty with his brother and Lil' Blue.

Seeing how the human challenged any monsters in their way, even pulling some out of bushes to dust, he could see this wasn't going to be the case.

 

He had threatened the human, saying if they kept going down the path they were going, he was going to have a great time later, before teleporting again.

He felt dizzy, using his magic too many times in a single day.

"boss, can i speak to ya?"

Papyrus grunted, but turned to Red.

 

"WHERE IS BLUE?"

Red jerked his thumb back in the direction of their house. "at home, why?"

"YOU USUALLY HAVE HIM SLUNG OVER YOUR SHOULDER WHILE OUT." Red could tell from the scowl that Boss didn't approve of this behavior, but was nonetheless worried at the sudden change.

"that's just the thing i wanted to talk to you about, boss."

 

He watched in slight amusement as Boss's brow bones raised in legitimate worry. Only their soulmate could bring out something like that in his bro.

Red swallowed, deciding being up-front about it would help much more than trying to dance around it.

"i think.. i think the human is going to try to hurt him." Red growled, unable to calm himself at the idea of his Blue being dust by the humans hands. Boss stiffened, before nodding.

"I KNEW THAT THERE WAS SOMETHING WRONG WITH THEM.." He muttered, face growing dark. "AS IF WE'D LET A HUMAN TOUCH OUR SOULMATE."

"don't go easy on 'em, boss." Red said, smirking at his boss's own twisted grin.

"I WASN'T PLANNING ON IT."

 

 

Blue's brain racked, trying to think of any reason Red would be acting like this. He knew that if he disobeyed their orders, he would regret it.

If he was _caught_ disobeying orders, he would regret it.

Blue hesitated, before pushing against Red's door.

No lock.

He allowed himself a small smile, finally happy that the two loved and trusted him so much.

 

He silently crept out the front door, the air of despair weighing him down. Blue grimaced, he knew by now that this was the general atmosphere of this universe by now.

But something was wrong.

It felt even heavier than usual.

He stared at the street of Snowdin, brow bones raised as he realized there were far less monsters on the street, and the ones left where keeping to themselves and looked very on edge, as if prepared to get into a fight at anytime.

 

Blue stared in puzzlement, trying to figure out why today was so different than any other day.

It was so similar to how his own Snowdin was acting in the middle of a-

Suddenly, it clicked together in his mind.

 

Blue prayed silently that his collar didn't block magic, before summoning whatever energy he had left to shortcut.

 

He gasped, falling to his knees from the energy of teleporting after going so long without using technical magic like that. He heaved, giving himself a moment to become grounded, before looking around. He saw the painted rock bridge in front of him, and-

A human with a familiar, unnerving smile behind him.

He turned, falling on his ass, shock overriding all other instincts. They giggled slightly, stepping towards the other.

"Sans..? You.. look different." They giggled again, high pitched and inhumane. "Don't look so scared." The human cooed, brushing the blade of their toy knife with their opposite hand.

 

Blue was near hyperventilating at being so closed to the one who _killed his friends, his brother-_ but one thought did prevail over the others.

"p-please.. please kill me."

The human froze, staring at the shivering skeleton. Blue flinched at the feeling of being CHECKed.

 

 ***SANS**  
***0.5 HP**  
***1 ATK**  
***1 DEF**  
***Comes from another world.**  
***Was forced into a soulbond.  
** ***Just wants it to end.**

 

The human blinked, but the grin grew wider at his stats. "Wow.. monsters really are fucked up, huh?" They cackled, before stepping closer to Blue.

"Don't worry, I'll **S A V E** you." The human stepped closer. "I will **S A V E** all of you."

They lifted their rubber knife high into the air-

A jagged bone struck through the human's soul, efficiently cracking and breaking it before they could land a finishing blow on Blue.

 

 **"sans."** Blue jumped at Red's terrifying growl, his eye glowing with magic. Blue cried out as his SOUL was wrapped with Red's magic, digging into his very being and causing the other to stay immobile. He choked on his own tears, falling to the ground, gripping at his rib cage.

 **"what the _fuck_ are you doing outside of my room."**

 

Red growled at his soulmate, watching in satisfaction as the other squirmed under his magic, grinning slightly as he dug his magic deeper into Blue's soul and was rewarded with a sharp cry.

He could feel pain and despair radiating off the SOUL, the SOUL repeating a mantra of _"HELP! HELP!! **HELP!!!"** _ in the midst of the other skeleton's panicking.

"SANS!" Red eased off his soulmate as he felt the Boss draw closer, he turned to see his bone attacks where already summoned, Boss staring at him, before moving to the skeleton writhing on the ground, sobs racking off his body.

"WHERE'S THE HUMAN."

"caught 'em off guard."

"WHY IS BLUE OUT HERE." Red held up his hands in a pacifying gesture at the infuriated tone of Boss.

"i told him to stay in my room."

Boss stared at him, before nodding and walking over to their smaller soulmate. He gasped loudly as Boss grabbed him by the collar, hands shooting up to grab at his wrists.

"SO YOU THINK YOU CAN JUST DISOBEY ORDERS? DO YOU HAVE ANY IDEA WHAT KIND OF DANGER YOU WERE IN?"

"i-i'm sorry!" Sans cried out, shaking like a leaf in the other's hold. "i just w-wanted to see-"

Red sighed, before joining his boss. "lay off lil' blue, boss. he probably was just confused. plus, he's scared out of his mind."

Boss's brow bones raised, before he could sense it. Blue's SOUL crying out for help with vigor.

Boss moved to cradle Sans closer, who tucked his face into Boss's shoulder at the warmth.

"We Won't Let The Human Near You." Boss reassured, rubbing the other's back almost soothingly.

Red sighed. His soulmate might have remembered the kiddo from his own timeline, and maybe Blue never saw a genocidal human before. Red had now calmed down enough to rationalize the idea that Blue might have just been worried for them, and scared once confronted with a threat who Blue may have assumed was an old friend.

Red smiled at the idea. His soulmate being worried enough to go against them made his own SOUL swell, and the idea that he could be Blue's knight, saving him from dangerous situations were he was just helpless, leaving Blue to rely and welcome on his and Boss's protection, boosted his ego.

But still, what Blue did was dangerous, and by glancing at Boss, he knew they weren't going to let Blue risk himself like that again.

"OF COURSE, THIS DOESN'T EXCUSE YOUR BEHAVIOR."

Red grinned as cute Lil' Blue froze in fear from the threat, clinging to Boss's shirt tighter.

 

Red had spent three days with Boss, telling him he had to create the perfect punishment for Blue. "it's gotta be something he won't forget, something new." Boss had begrudgingly agreed and held off on doing anything to Blue.

It was on the fourth day Red burst through the house door, his grin wide and predatory as he grabbed Blue, yelling at Boss that they'd be gone for the day, before teleporting away.

 

When Red had returned, Blue had a few tear stains on his cheekbones and Red looked like the cat who got the cream. "boss, we got something to show ya."

 

He positioned Blue to be laying down on the couch, half his back pressed against Red's torso, Boss staring at his soulmate intently from in between his legs.

"open 'em wider, baby." Red nudged Blue's legs apart further, who only whined quietly in response. "boss, i found a good punishment for 'em."

Boss stared at him, intrigued, before Red slowly moved Blue's skirt up, revealing his already summoned ecto-pussy.

On the hood of his clit, there was a small barbell pierced through the ecto-flesh. The bar laid across his clit. Blue made a noise that could only be described as mortified, turning to hide his face.

"look at boss." Red ordered, turning Blue's face himself.

"now, we can't touch him for another four to six weeks, but he'll end up being even more sensitive, and with this on, he can't dispel his cute little pussy." Red grinned, looking up at Boss.

"AND THE ACTUAL PROCESS OF GETTING HIS CLIT PIERCED?" Boss questioned, staring at the barbell with curiosity.

Red looked down at Blue expectantly. Blue choked out a response;

"i-it hurt.." He admit, shifting under Boss's stare. He let out another strangled cry as Boss's gloved fingers brushed against the sore area.

"hey, you really can't touch him for a while. it'll end up hurting him worse in the long run." Red frowned. Boss only nodded.

"THIS IS AN ACCEPTABLE PUNISHMENT. GOOD JOB, RED." Red grinned at the praise.

"AND BLUE-" Blue stared up at the other skeletons, eye lights small.

"YOU ARE NOT ALLOWED TO REMOVE YOUR PIERCING. ONLY MYSELF OR RED IS ALLOWED TO REMOVE IT." Boss kissed the top of his skull despite his demanding tone.

"AND YOU WILL NOT..?" Boss questioned, smirking.

Blue swallowed, trembling.

"d-disobey orders."

**Notes for the Chapter:**

> thetrueanon requested clitoris piercing! attempted suicide, murder, possesive behavior, delusions (i hope everyone understands the uf bros are delusional. sans doesnt want to be with them, and doesnt love them. any conclusions the uf bros are unreliable narrators. pls dont think sans in any way enjoys being with these two lol) violence, ecto-bodies, and i think that's it..? tell me if i missed something!  
> plans and what's been going on with me~~  
> hey guys, this week was stressful. i wrote this chapter to blow off some steam because last night was bad for me. that's why i continued the uf story despite just having another story with them. sorry i swear i'm working on the other chapters-  
> on my down time, i've been slowly planning another story. hope that you all see it soon! i'm trying to make chapters longer for that one.  
> also, i'm thinking of dropping my tumblr? just in case any of you want to message me/ask me stuff, and that way i can post drabbles that dont exactly fit in this story, but take place in the timeline, and you could all see my art n stuff. i could just post a separate drabble book too, whatever works.  
> i'm gonna push through the remaining sequels, then move onto some more au's, and then add sequels and continuations as i see fit! if you requested something, please be patient. i swear i will get to it!  
> love you all <3


	10. Limits (Lust Alternative)

**Summary for the Chapter:**

> in which, lust doesn't exit grillby's in time to save sans from that bear

**Notes for the Chapter:**

> GOdD i don't even know what happened with this chapter. i had a bunch of ideas and it was gonna be super long and cool but like!! everything was bad! so i gave up for a while lol  
> this is? decent i guess? but anyways i'll hopefully start updating faster again!  
> everyone who commented something nice or gave a kudos i legit love you <3  
> warnings are at end notes!  
> oh and this is NOT a sequel to the original lust, i'm doing that either next or soon. this is if that bear fucker got to sans before lust could exit grillbys, if you remember the original

"ghk- fuc-ck!"

Sans sobbed as his magic was stretched to its limits once more, gripping the arms of whatever monster was pushing into his cunt now.

 

He had absolute no idea how long this seemingly endless group of monsters have been fucking him. He had been teleported into a random universe, barely having time to look around before he was grabbed by the bear he would usually see outside of his own Grillby's. He initially just tried to tug away from the bear, before his heat kicked in and the other monster was able to sink magic into his SOUL, efficiently knocking him out.

 

When Sans woke up, he had no idea were he was taken. Judging by the grayish color of the dark room, Sans would guess he was somewhere in the Capital.

 

He didn't have time to dwell on it, however, as only moments after he awoke, Sans was grabbed forcefully by large hands at the back of his skull, and was pushed against a clothed boner.

Sans had panicked once realizing what he was shoved against, and tried to push the other away. His arms wouldn't budge. Guessing by the pressure on his wrists, his wrists were tied behind his back. The monster restraining him only grunted, unzipped his pants too free his hard cock, and forced open Sans's jaw with one hand.

 

Since then, and only god knows how long ago that was, more monsters were drawn to that room, the intensity of Sans's heat drawing them, like moths to a flame.

 

Sans choked around the cock currently forced into his mouth, not coherent enough to do much but let the other monster fuck roughly against his skull, tongue lolling out of his mouth. He clamped around the other cock deep in his pussy, brought to another, now painful orgasm. He had no idea how many times they've made him cum so far, but stars did it hurt now. Monsters seemed to line up at whatever hole interested them the most, some plowing into his ass, some preferring his now stretched and leaking pussy,  
others simply thrusting into his mouth.

He felt his magic stretch more as the monster underneath him came, shoved deep into his throbbing cunt. His ecto-stomach, absorbing an overload of magic, has enlarged, excess magic spilling from his cunt and ass whenever a monster wasn't plugging up the holes with their cocks.

Sans sobbed as the monster underneath him was near immediately replaced, eye sockets slipping closed. It was all too much, it had all been too much. His heat was long sated from the endless fucking, his magic was torn and over sensitive to the point it just _hurt,_ and he just wanted to stop, please just _stop-_

 

 

Sans slowly gained consciousness again, groaning in pain at the discomfort in his stomach and cunt, hiccuping as he felt flesh pound against his shaking bones. His eye sockets widened and he cried out in shock and fear as his eye lights focused on another monstrous cock splitting him open, stomach even larger than when he lost consciousness.

 _"t-they were still going?"_ Sans realized in absolute horror, shuddering as the monster behind him gripped his femurs, thrusting deep into the small skeleton.

 

Sans was shaking, the monster finally releasing more cum deep in his magic, pulling out and watching in satisfaction as his magic, mixed with others, began to spill out from his abused cunt.

 

Sans was placed on the floor, a rough kiss being pressed against his teeth before the monster left. The skeleton just continued crying, surprised he still had tears to shed.

 

Despite the monsters surrounding him, none made a move towards him, which confused Sans further. Weren't they going to let him go now that they were satisfied...?

 

His eye sockets widened as a monster resembling an octopus pushed through the door, two monsters locking it behind him. Sans attempted to crawl back and away.

"n-no, no please please-" He cried as tentacles began to wrap around his ankles, pulling him closer. "i can't, i can't please-!" The monsters surrounding him began to yell out suggestions towards the monster.

 

"Take his ass and pussy at once!"

"Breed him good!"

"Wreck his cute pussy!" 

 

Sans could only let out choked, confused sounds as cool tentacles slid over his hot, oversensitive bones, slowly pulling him up into the air. Tentacles gripped at his spine, pulling apart his legs to expose his slick, cum filled pussy to the crowd once more. He shivered as one of the thick appendages slid across his cunt, stopping to press against his abused clit.

 

"s-stop..." He tried again weakly, tentacles easily restraining his weak limbs. The small skeleton cried out in fear as the tentacle rubbing insistently at his pussy had begun to slowly push in, easily slipping past the stretched hole, it's natural lubricant and the magic coating his inner walls only helping the smooth thrusting.

The tentacle kept a slow, consistent pace, one that was strangely soothing on his aching magic. It never pushed too far, but just enough to get the slightest burn of pleasure he didn't even know he could feel after what felt like hours of nothing but pain. Sans sobbed, spasms racking his body as his the tentacle found the one spot most of the previous monsters seemed to have ignored, and had began to spend most of it's time massaging against that spot.

 

Sans could only weakly rocking back against the tentacle that provided him the slightest bit of comfort, small moans slipping from his mouth.

Another orgasm ripped through him, whatever magic that was expelled coating the tentacle inside him. Sans whined, feeling faint again from his magic slowly depleting.

He only forced himself to stay conscious as the tentacle fucking _grew_ inside of him, his stretched magic straining once more to accommodate the new size.

"w-wha.." Sans blinked away tears to look down, just in time to see an egg slip past the end of the tentacle and into his translucent magic.

 

Sans screamed silently, another egg already pushing against his walls, an uncomfortable foreign weight in his abdomen. Sans tried to squirm away, although it was a pathetic attempt in all. The monster did not let up, two tentacles pulling his legs apart even further as the third fell into place.

 

At the fourth, his magic snapped into existence on instinct, a womb. The eggs pushed past his newly formed cervix to rest in his womb, although the feeling wasn't any less pleasant for the skeleton. By the sixth egg, Sans swore his magic was about to burst. The feeling was no longer a mild discomfort, it ached, and this monster just wasn't stopping. His thrashing once again died out, leaving a broken skeleton who could only make noises of pain and cry.

 

The monster finally stopped after twelve eggs, gently setting Sans back down on the ground, running it's tentacles over his bones in a way that, if it wasn't for this monster just raping him, Sans would find soothing. He panted harshly, his ecto-stomach bulging from the eggs.

 

Sans shuddered, keening as he felt a hand on his stomach, opening his eyes slightly to see a few monsters have now formed somewhat of a circle around him, the one who had placed his hand on Sans's stomach kneeling, a lustful smile on his face.

"Guess we need to fertilize these eggs, huh?"

 

Sans didn't have the energy to cry, scream, or do anything as they continued to have their way with him.

**Notes for the Chapter:**

> gang bang/orgy, oviposition, tentacle sex, noncon somnophilia, crying, overstim to the point it huurts biiitch, lemme know if i forgot something bc i feel like i am...  
> check out my tumblr, boop ---> https://sansfxcker.tumblr.com/  
> polybones is out! if you want some cute stuff after this... uh.... dark story.... maybe check it out! i've got some other various one shots too  
> oh and i'm going back soon to edit some of my old chapters. i don't have a beta reader, and i end up posting things that have mistakes in them, or i could word better. so hopefully i'll go back and fix anything minor soon!


	11. Pomegranates (UL Sequel)

**Summary for the Chapter:**

> Lust stared at Sans, eyelights wide in shock. "y-you don't have to do that-"
> 
> "i want to."

**Notes for the Chapter:**

> oh shit its me did you miss me heyy  
> y'all good news i'm finally getting time to update again and im excited as hell! also, i'm dumping all continuations past this in another book, and i'll let you guys know when thats updating. Once i finish the horror and sf one, i'll create a new book and start working on any continuations you guys already requested while working on chapters for this book. I just don't want this to become super super cluttered.  
> hey this one should have no warning bc for once its all super consensual and cute! check end if you want more of my own vision for lust. hope u guys like a slightly cuter chapter than this book usually gets, lol.

Lust tentatively peeked through the door. ".. comic?"

He then had to dodge a heart-shaped pillow flung in his direction.

 

The skeleton poked his head through the door again, lopsided smile more uneasy. "... i'm sorry?" This would be the fifth time he had apologized.

 

"i feel like i'm dying." Sans groaned, looking up to half-heartedly glare at Lust.

 

"i thought you were dying!!" The other took this as a sign he was allowed to enter the room again. stepping forward. "i didn't know one HoPe was.. normal for you."

Sans noted the other's small drop in mood once mentioning his HoPe again. Lust, after what Sans swore was hours of continuous torture just teetering on the line of pleasure, freaked out once his max HoPe did not change. The sore, exhausted skeleton had explained quickly one HoPe was normal for him, before promptly passing out.

He woke up to next morning to aching bones and Lust handing him more water. Sans threw the water bottle at Lust after chugging half of it, successfully herding Lust out of the room. Thus began the precarious game of Lust trying to apologize for his enthusiasm, and Sans finding more things to throw.

 

"i really was just trying to help." Lust looked regretful, no ill-intent in his words. Sans sighed, not unkindly, as he realized Lust was probably worried that he somehow hurt the other. So he threw him a bone.

"how does fucking me out of my mind help." He grinned lazily, watching Lust's eyes light up and a smirk tug the corners of his mouth back up.

 

".. helping through a lil' sexual healing..?" Sans stared at the other for a few seconds, before laughing loudly, half from the stupid pun, half from relief that Lust recognized no real harm was done.

 

Well, almost.

 

"laughing was a bad idea. everything hurts." He wheezed, making Lust start to fret over him again.

 

After, once again, Lust was kept from panicking over Sans's current state, the two sat in silence. Sans turned to the other skeleton, who was on his phone, checking his brothers messages, nothing more than confirmations he was okay and would be returning home soon.

Without really thinking about it, Sans CHECKED Lust.

 

*SANS  
*10/10 HP  
*1 ATK  
*1 DEF  
*Is in a constant state of heat.  
*Worries about you.

 

"comic..?" Sans shot up, face flushed light blue as it registered what he had done.

"sorry, sorry-" Sans babbled, avoiding Lust's concerned gaze. "i was just curious.." His mind, however, was racing. 10 HoPe. That's one more zero than Sans ever remembered having.

 

"no, it's fine." Lust reassured him, giggling. "i guess you do deserve to know what this world is like."

 

"we're... us monsters... stars, i've never had to explain this to anyone before." Lust laughs, cheekbones tinted purple. "we're in a constant state of heat now, because of some core malfunction or something, it's hard to explain.."

"But, if a monster doesn't end up getting relief after a period of time, their HoPe drops. a.. a ton of monsters ended up falling down the first few years this happened.." Lust's eyes filled with sadness even as his flush grew brighter. "i-i think the only reason i survived is because paps helped me through it all.. heheh.."

Oh. Sans's eyelights widened, and his own face now matched Lust's.

"but, monsters started helping each other out, and it's not too bad anymore. Now we're all.. shameless, honestly. papyrus helps out monsters who can't find partners now that he joined the royal harem, and everyone's kinda used to it now."

Lust turns to Sans, gaze softening. "you're heats were just an intense as a monster here when they're close to falling down, and it really, really freaked me out. you seem alright, for being me."

"heh, same to you." The two skeletons sat in comfortable silence for a few more minutes, before Sans broke the ice again;

"can i... work on the machine? so i can get back to my universe?"

"not enough time for round two?~" Lust laughed, narrowly dodging a pillow swipe from Sans. "of course you can. we can look at it later tonight, papyrus will be home by then. we'll need to find a way to explain this.." Lust trailed off.

 

Another moment of silence. Sans glanced over at Lust. "did you get off last night?"

"what?!" Lust seemed thrown off, face bright purple again. "last night was all about you-"

"do you care if i?"

Lust stared at Sans, eyelights wide in shock. "y-you don't have to do that-"

"i want to." He reassured, placing a pillow beneath his kneecaps as he placed himself on the floor, situated in between Lust's legs. "consider it an act of gratitude for saving my life." Sans winked, finding immense pleasure in how Lust's eyelights turned heart shaped.

His entire lower body was much too sore for anything more strenuous than a blowjob, but Sans figured if it legitimately helped monsters down here that there was no harm in a quick favor. Plus, Lust did help him through his heat.

Sans shuddered, wondering what would have happened if he went into full blown heat in the middle of town. He tries to erase that thought from his mind, focusing on the task ahead.

 

Lust's leather pants were undone and partially pulled down his thighs, just enough for his already summoned cock to bob forth. Sans smirked, eyebrows raised. No underwear was expected, but.. 

"so excited already?"

 

Lust grinned. "hey, this is my dream, after all." Sans chuckled, gripping the base with one hand. He begins gently rubbing the shaft, before leaning forward, ecto-tongue summoned in his mouth. He swipes his tongue over the head of Lust's cock, eye lights never leaving the others hazy heart ones. Sans continues the motion, moving to flick at his frenulum, grinning as he was rewarded with a particularly loud moan. Mindful of his teeth, Sans cushioned his cock with his tongue and slowly inched down, tongue  
paying special attention to the head of Lust's cock. Lust was keening above him, restraining himself from bucking into Sans's awaiting mouth. The original skeleton glanced up at Lust with lidded eyes. Lust groaned appreciatively, near embarrassed how fast his orgasm was approaching. But he also couldn't get the sounds Sans made last night- ones of pure pleasure that filled Lust's dreams that entire night. Even the thought of Sans doing this was something Lust had already accepted would only happen in his wildest fantasies.

 

Sans sensed Lust was close, and so he wrapped his index finger and thumb around the base of his cock, applying just enough pressure that always worked for him, and jerked upward only a few inches, repeating in a few quick successions. That sent Lust over the edge, the skeleton crying out as he thrust up into the air, magic filling Sans's mouth.

 

Lust breathed heavily as he felt Sans pull away from his softening cock, dispelling the magic once he was sure Sans was competely off it. He glanced up at the other, ready to apologize for not giving a warning and to find tissues for Sans to use, only to freeze

Sans had wiped off any access magic from the corners of his mouth, bringing his phalanges to his tongue. He made quick work of licking them clean, before humming thoughtfully.

"taste like... pomegranates?" Sans browbones were raised, lazy grin still visible on his face.

 _Holy shit._ Lust just connected the dots. Sans had swallowed his magic completely. That's... insanely hot.

 

"y'know, i really don't think we're that different." Lust laughs, laying back on his bed.

"disagree. i think i taste like something worse, like ketchup."

Lust waggled his browbones. "want me to find out?"

"maybe after a nap." Sans sighed, laying down next to Lust.

"if you fall asleep here, i'm going to cuddle you." Lust teased.

"maybe that's what i want.." Sans yawned, before his eye sockets closed.

 

 

 

 

Papyrus got home late, late enough that he missed cooking a passion filled dinner for him and his brother. The past few days have been busy in the harem, but things have calmed down enough that he was allowed home.

He pushed open the door to his home, expecting to find his brother lazing on the couch per usual. However, he did not expect to be nearly assaulted with a heavy scent, not one of any monsters Papyrus had already met, but something new, intermingled with his own brothers. Had his brother brought someone home? The smell was thick enough that Papyrus would consider it to belong to a monster who was close to falling. Maybe Sans finally began to take his escort job seriously..?

 

He wandered up the stairs, more perplexed as he didn't hear any noises he would now associate with sex. "BROTHER?" Papyrus was beginning to get a bit concerned, Sans had an awful habit of teasing the citizens around town before leaving them high and dry. Perhaps one of those citizens in a heat hazed state of mind decided to finally inflict revenge on his dear brother, and something terrible happened?-

Papyrus was beginning to freak himself out now. He opened Sans's door, mentally prepared for whatever laid inside-

 

He found two sleeping, identical skeletons, both forgetting to turn off the light before falling asleep, arms wrapped around each other.

 

Paps stared at the two, dumbstruck as his mind processed the idea of his brother having a clone-

_There were two of his brother oh my stars_

 

With no other option, he decided to wake up his older brother to interrogate him on why he was canoodling with _himself-_

"SANS!!"

**Notes for the Chapter:**

> so i think my vision of lust is different from the original creators idea for it? just a bit maybe? anyways i'll definitely continue this, were paps wakes them up and who knows what happens from there~~ also a lot of hints on to why sans was targeted last chapter despite him being in heat!  
> in this, lust and sans actually end up! liking each other a bit? its surprising right! anyways i want these two to be like. the one beacon of hope in a sea of neverending sans angst. give that boy some love, and who better than lust to give it to him?  
> check out my tumblr whooo -----> https://sansfxcker.tumblr.com/  
> bye love you all hopefully see you soon! <3


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